Plaster ring



FIG. 1 is a front-right perspective view of a plaster ring in accordance with the present design;

FIG. 2 is a rear-left perspective view of the plaster ring shown in FIG. 1;

FIG. 3 is a front view of the plaster ring shown in FIG. 1;

FIG. 4 is a rear view of the plaster ring shown in FIG. 1;

FIG. 5 is a top view of the plaster ring shown in FIG. 1;

FIG. 6 is a bottom view of the plaster ring shown in FIG. 1;

FIG. 7 is a left side view of the plaster ring shown in FIG. 1; and,

FIG. 8 is a right side view of the plaster ring shown in FIG. 1. 

CLAIM The ornamental design for a plaster ring, as shown and described. 